Whats the rule on time violations?

Are they treated like code violations - i.e. warning, then point, game, match penalty? Or is it up to the umpire's discretion.

I really hope the umpire does a good job enforcing the time constraint against Nadal, and also watch out for any coaching. Ljubicic is not the first player to complain about his delaying, even the commentators picked up on it.

Nadal fans defend this behaviour by saying that he's not doing this as a tactic, he's just mentally preparing himself, or that he needs time to recover. Nadal says 'I do everything proper'. Whatever. Its obviously illegal and he should be penalised for it. So should every other player who does it as blatantly.